What "slip" means here
A tire makes the most grip when it is turning a little faster than the car is moving. The traction control function measures that difference, and this table sets how much of it is allowed.
- FWD and RWD: slip is the speed difference between the driven and undriven wheels.
- AWD: with no undriven wheels to compare against, slip is the difference between the fastest and slowest wheel speed sensors.
When measured slip goes above the value from this table, traction control applies whichever Cut Method you picked to bring it back down. How hard it cuts is set in cut percentage.
Mapping the table
The table can be up to 3D, with an 8 x 8 grid. Vehicle speed is a natural axis, because a fixed speed difference means much more at low speed than at high speed. Gear, or a dash knob for driver adjustment, are other common choices.
Our starting point
- Start with a fairly generous allowance so the system only catches real wheelspin.
- Log driven and undriven speeds, measured slip and the cut. Tighten the table where the car loses time to spin, and loosen it where the cut is bogging the engine.
- Make sure wheel speed sensors are calibrated first. A wrong tire size looks exactly like slip.
Sensor wiring is covered in traction control wiring, and our traction control user guide goes further.
